Browse Topic: Braking systems

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Simulation-Based Investigation and its Experimental Validation of the Thermal Behaviour of a Battery Electric City Bus2025-01-0266To be published on 07/02/2025
Electrification of city busses is an important factor for decarbonisation of the public transport sector. Due to its strictly scheduled routes and regular idle times, the public transport sector is an ideal use case for battery electric vehicles (BEV). In this context, the thermal management has a high potential to decrease the energy demand or to increase the vehicles range. The thermal management of an electric city bus controls the thermal behaviour of the components of the powertrain, such as motor and inverters, as well as the conditioning of the battery system and the heating, ventilation, and air conditioning (HVAC) of the drivers’ front box and the passenger room. The focus of the research is the modelling of the thermal behaviour of the important components of an electric city bus in MATLAB/Simscape including real-world driving cycles and the thermal management. The heating of the components, geometry and behaviour of the cooling circuits as well as the different mechanisms of
Schäfer, Henrik, Meywerk, Martin, Hellberg, Tobias
Technical Paper
Kinetic Energy Recovery: Assessment on the impact of Permanent Magnet Synchronous Motor and Battery Dynamic models2025-01-0303To be published on 07/02/2025
This paper examines the influence of a detailed dynamic model of a Surface Permanent Magnet Synchronous Motor (SPMSM) on the accurate evaluation of kinetic energy recovery during braking in a mild hybrid vehicle. The model, implemented in MATLAB Simulink, is based on the motor's DQ equivalent circuit, accounting for transient effects, inductance variability, and magnetic saturation. Also, a 2nd Order Thevenin Equivalent model of the battery is used in order to take into account the bus voltage variability. Simulations reveal that the dynamic model predicts significant variations in energy recovery potential, with differences of up to 25% compared to static models under specific braking conditions. These discrepancies are particularly pronounced during high-speed high-torque transitions, where transient electrical behaviors strongly influence energy recovery. The model’s accuracy enhances the reliability of energy simulations, especially in scenarios involving frequent or intense
Lombardi, Simone, Federici, Leonardo, Tribioli, Laura, Bella, Gino
Technical Paper
Development and Evaluation of a Combined Driveline Oscillation and Traction Controller Using Model Predictive Control and Reinforcement Learning: A Comparative Case Study2025-01-0291To be published on 07/02/2025
In electric vehicles, the control of driveline oscillations and tire trac- tion is critical for guaranteeing driver comfort and safety. Yet, achiev- ing sufficient driveline control performance remains challenging in the presence of rapidly varying road conditions. Two promising avenues for further improving driveline control are adaptive model predictive control (MPC) and model-based reinforcement learning (RL). We de- rive such controllers from the same non-linear vehicle model and vali- date them through pre-defined test scenarios. The MPC approach em- ploys input and output trajectory tracking with soft constraints to en- sure feasible control actions even in the presence of constraint viola- tions and is further supported by a Kalman filter for robust state estima- tion and prediction. In contrast, the RL controller leverages the model- based DreamerV3 algorithm to learn control policies autonomously, adapting to different road conditions without relying on external infor- mation
Uhl, Ramón Tamino, Schüle, Isabel, Ludmann, Laurin, Geist, A. René
Technical Paper
Methodology for Fast-Running, Time-Resolved Simulation of Non-Exhaust Particle Emissions from Brake Wear Abrasion2025-01-0275To be published on 07/02/2025
Non-exhaust particle emissions, particularly those generated by brake wear, are a significant source of fine particulate matter in urban environments. These emissions contribute to air pollution and pose serious health risks, particularly in densely populated areas. While vehicle exhaust emissions have been extensively studied and regulated, the contribution of non-exhaust sources, including brake wear, remains a critical factor in air quality management. This paper presents a novel methodology for fast-running, time-resolved simulation of non-exhaust particle emissions, specifically those from brake wear abrasion. A 3D CFD model computes the turbulent flow field around the disc brake. The resulting information on the convective air cooling is applied as boundary conditions on a 3D thermal model. This thermal simulation setup is compared and verified with experimental data from literature. The 3D numerical models produce data and boundary conditions for an efficient 1D numerical
Herkenrath, Ferris, Lückerath, Moritz, Günther, Marco, Pischinger, Stefan
Technical Paper
Leveraging LLM-based AI Agents for Boosting the Vehicle Testing Process2025-01-0300To be published on 07/02/2025
The validation process in research and development involves several complex stages, including test requests, planning, execution, and the analysis and evaluation of results. In the automotive domain, compliance with regulatory standards, such as those required for Euro 7 homologation, adds an additional layer of complexity. Implementing these regulations into operational validation workflows and ensuring their seamless integration with supporting tools remains a significant challenge. Recent advancements in Large Language Models (LLMs) have introduced innovative use cases across various domains. In particular, AI agents powered by LLMs demonstrate immense potential by autonomously performing complex tasks while utilizing user-defined tools. This capability extends far beyond traditional applications like knowledge management or text generation typically associated with LLMs. In this paper, we explore how a modern AI agent can be developed and integrated into existing IT tools for test
Unterschütz, Stefan, Hansen, Björn
Technical Paper
Wheel Hop Detection in High-Torque Vehicles: A Machine Learning Approach with Focus on Data Coverage and Model Generalization2025-01-0271To be published on 07/02/2025
Wheel hop is a vibration phenomenon that occurs in cars with a high torque during high accelerations from low speed. Drivers perceive wheel hop as vertical oscillations in the vehicle frame. In severe cases, it can lead to component damage or deformation. Therefore, the affected vehicles must be safeguarded against these vibrations through safe component design and additional software-based functions. Conventional software-based solutions such as the traction control system (TCS) are not explicitly designed to prevent wheel hop. These systems often intervene too late and apply abrupt torque adjustments that compromise driving comfort. Based on observations on real measurements the TCS intervention in some cases leads to an amplification of the wheel hop effect. To address these challenges, we propose a novel approach based on machine learning (ML) for the early detection of wheel hop by leveraging real-time measurements from a rear-wheel drive vehicle. Unlike conventional methods, our
Chehoudi, Moatez, Moisidis, Ioannis, Sailer, Marc, Peters, Steven
Technical Paper
Longitudinal Dynamic Metrics for Describing and Developing the Deceleration Behavior of Vehicles in the Concept Phase2025-01-0264To be published on 07/02/2025
The brake system is a critical safety component in motor vehicles. Advances in the electrification of the powertrain and the rise of autonomous driving technologies are profoundly influencing the brake system, driving innovative approaches to brake concepts and necessitating the development of new deceleration strategies. A significant technological advancement is the decoupling of the driver from the brake system through Brake-by-Wire technology. A crucial attribute is the attainment of a consistent and concept-independent deceleration behavior and pedal feel. To establish a consistent and OEM-specific deceleration behavior and pedal feel in the early development phase, objective criteria and perceptual thresholds are required, describing the desired subjective braking behavior. Moreover, objective criteria are indispensable for the virtual phase of the vehicle development process. In this article the focus is in deceleration from a straight-ahead drive. To identify objective criteria
Biller, Ralph, Udovicic, Matej, Ketzmerick, Erik, Kirch, Sebastian, Mayr, Stefan, Prokop, Günther, Wagner, Andreas
Technical Paper
Development of the Central Coordinated Motion Control System for Pure Electric Vehicles2025-01-0188To be published on 06/16/2025
The IM L6 is the fourth product under the IM brand, featuring both rear-motor two-wheel drive and dual-motor all-wheel drive configurations. This article introduces the Ling Xi Digital Intelligent Chassis system of the IM L6, which includes air springs, CDC (Continuous Damping Control), rear-wheel steering system, braking system, front-wheel steering system, and electric drive system. The study explores how adjusting the damping of the CDC achieves a more comfortable damping effect. Through precise control of the rear-wheel steering system, the vehicle achieves smaller turning radii, crab walk capability, optimized response in moose test conditions, and improved performance on split-friction surfaces. By coordinating the IBS (Intelligent Brake System) and VMC (Vehicle Motion Control), an exceptionally comfortable braking experience is achieved.
Zhou, Yuxing, Li, Wen
Technical Paper
Electric Bus NVH Challenges and Refinement Using Innovative Approach2025-01-008005/05/2025
The trend towards electrification propulsion in the automotive industry is highly in demand due to zero-emission and becoming more significant across the world. Battery electric vehicles have lower overall noise as compared to conventional I.C Engine counterparts due to the absence of engine combustion and mechanical noise. However, other narrowband and tonal noises are becoming dominant and are strongly perceived inside the cabin. With the ongoing push towards electrification, there is likely to be increased focus on the noise impact of gearing required for the transmission of power from the electric motor to the road. Direct coupling of E-motors with Axle has resulted in severe tonal noises from the driveline due to instant e-motor torque ramp up from 0 rpm and reverse torque on driving axle during regenerative braking. The tonal noises from the rear axle during vehicle running become very critical for customer perception. For automotive NVH engineers, it has become a challenge to
Doshi, Sohin, Kalsule, Dhanaji, Sawangikar, Pradeep, Suresh, Vineeth, Sharma, Manish
Technical Paper
Brake Noise CAE Enhancement with the Synergy between Design of Experiments and Machine Learning2025-01-012405/05/2025
The digitalization of industrial systems has led to increased data availability. Machine learning (ML) methodologies are now commonly used for data analysis in industrial contexts. Not all contexts have abundant data; sometimes data collection can be scarce or expensive. Design of Experiments (DOE) is a technique that provides an informative dataset for ML analysis when data are limited. It involves systematically designing experiments to collect relevant data points with regression models. Disc brake noise is a challenging problem in vehicle noise, vibration, and harshness (NVH). Different noise events occur under various operating conditions and across frequencies (1-16 kHz). To enhance computer-aided engineering (CAE) techniques for brake noise, ML is used to generate additional data. Sequential experimentation in DOE aligns well with ML’s ability to continuously learn and improve as more data become available. DOE is applied in CAE to collect data for training ML models. ML helps
Song, Gavin, Sridhar, Gurupriya, Vlademar, Michael, Venugopal, Narayana
Technical Paper
Model Based NVH Simulator for Virtual Development2025-01-005905/05/2025
For mature virtual development, enlarging coverage of performances and driving conditions comparable with physical prototype is important. The subjective evaluation on various driving conditions to find abnormal or nonlinear phenomena as well as objective evaluation becomes indispensable even in virtual development stage. From the previous research, the road noise had been successfully predicted and replayed from the synthesis of system models. In this study, model based NVH simulator dedicated to virtual development have been implemented. At first, in addition to road noise, motor noise was predicted from experimental models such as blocked force and transfer function of motor, mount and body according to various vehicle conditions such as speed and torque. Next, to convert driver’s inputs such as acceleration and brake pedal, mode selection button and steering wheel to vehicle’s driving conditions, 1-D performance model was generated and calibrated. Finally, the audio and visual
Park, Sangyoung, Dirickx, Tom, Kang, Yeon June, Nam, Jeong Min, Gonçalves, Vinícius Valencia
Technical Paper
Simulation and Experimental: Enhanced Stability Control of Electric Vehicle Based on Phase Plane Boundary Analysis10-09-02-001705/05/2025
To optimize vehicle chassis handling stability and ride safety, a layered joint control algorithm based on phase plane stability domain is proposed to promote chassis performance under complicated driving conditions. First, combining two degrees-of-freedom vehicle dynamics model considering tire nonlinearity with phase plane theory, a yaw rate and side slip angle phase plane stability domain boundary is drew in real time. Then based on the real-time stability domain and hierarchical control theory, an integrated control system with active front steering (AFS) and direct yaw moment control (DYC) is designed, and the stability of the controller is validated by Lyapunov theory. Finally, the lateral stability of the vehicle is validated by Simulink and CarSim simulations, real car data, and driving simulators under moose test and pylon course slalom test. The experimental results confirm that the algorithm can enhance the maneuverability and ride safety for intelligent vehicles.
Liao, Yinsheng, Zhang, Zhijie, Su, Ailin, Zhao, Binggen, Wang, Zhenfeng
Journal Article
Development of an Imperceptible Brake Failure Control Technology and Real Vehicle Application10-09-02-001504/26/2025
With the advancement of control technology in the automotive field, there is a possibility of cross-system redundant control between various actuators. As for the braking system, current brake-by-wire system often uses mechanical backup braking methods to give the vehicle a certain braking capacity after failure. However, in the mechanical backup braking mode, the brake master cylinder is connected to the supporting wheel cylinder, and the brake assist is lost, which leads to an increase in brake pressure and makes it difficult for the driver to step on the brake pedal. Meanwhile, due to the limitation of the brake master cylinder stroke, the maximum braking deceleration of the vehicle is only 3 m/s2 after the driver fully presses the brake pedal. The above two defects greatly affect the safety of the vehicle during backup braking. To solve the above problems, this article takes electric vehicles as the research object, designs a new type of hydraulic circuit for the braking system
Tian, Boshi, Li, Liang, Liao, Yinsheng, Lv, Haijun, Hu, Zhiming, Sun, Yue, Qu, Wenying
Journal Article
Development of a Robust Framework for Fault Detection and Quantification in Automotive Drum Brakes Using Vibration Measurements and ANN10-09-03-002404/15/2025
Passenger safety is of utmost importance in the automotive industry. Hence, the health of the components, especially the brake system, should be effectively monitored. On account of the significance of artificial intelligence in recent times, any brake fault resulting during operation can be accurately detected using a combination of advanced measurement techniques and machine learning algorithms. The current study focuses on developing and evaluating a robust framework to quantify and classify the faults of a general automotive drum brake. For this purpose, a new experiment for a drum brake, which can be operated under a controlled environment with known levels of faults, is developed. The experiment is instrumented to measure the fundamental dynamic signals (such as brake torque, the angular velocity of the brake drum, and brake shoe accelerations) during a braking event. The response signals from several experiments with various faults and operating conditions serve as the input
Yella, Akash, Bharinikala, Yuva Venkat Ajay, Sundar, Sriram
Journal Article
Automatic Emergency Braking (AEB) System Performance TestingJ3087_202504 (Current)04/14/2025
This document describes an SAE Recommended Practice for Automatic Emergency Braking (AEB) system performance testing which: Establishes uniform vehicle level test procedures Identifies target equipment, test scenarios, and measurement methods Identifies and explains the performance data of interest Does not exclude any particular system or sensor technology Identifies the known limitations of the information contained within (assumptions and “gaps”) Is intended to be a guide toward standard practice and is subject to change on pace with the technology Focuses on “Vehicle Front to Rear, In Lane Scenarios” expanded to include additional offset impacts This document describes the equipment, facilities, methods, and procedures needed to evaluate the ability of Automatic Emergency Braking (AEB) systems to detect and respond to another vehicle, in its forward path, as it is approached from the rear. This document does not specify test conditions (e.g., speeds, decelerations, clearance gaps
Active Safety and Driver Support Systems Standards Committee
Recommended Practice
Automotive Air Brake Hose and Hose AssembliesJ1402_202504 (Current)04/14/2025
This SAE Recommended Practice covers minimum requirements for air brake hose assemblies made from reinforced elastomeric hose and suitable fittings for use in automotive air brake systems, including flexible connections from frame to axle, tractor to trailer, trailer to trailer, and other unshielded air lines with air pressures up to 1 MPa, that are exposed to potential pull or impact. This hose is not to be used where temperatures, external or internal, fall outside the range of -40 to +100 °C. Provisions for extreme low temperature performance testing to -54 °C are included in the document.
Hydraulic Hose and Hose Fittings Committee
Technical Standard
Compatibility between Stability and Curving Ability of Railway Vehicles Using Conventional and Unconventional Bogie Frame Models02-18-03-001404/09/2025
This article analyses the fundamental curving mechanics in the context of conditions of perfect steering off-flanging and on-flanging. Then conventional, radial, and asymmetric suspension bogie frame models are presented, and expressions of overall bending stiffness kb and overall shear stiffness ks of each model are derived to formulate the uniform equations of motion on a tangent and circular track. A 4 degree of freedom steady-state curving model is formulated, and performance indices such as stability, curving, and several parameters including angle of attack, tread wear index, and off-flanging performance are investigated for different bogie frame configurations. The compatibility between stability and curving is analyzed concerning those configurations and compared. The critical parameters influencing hunting stability and curving ability are evaluated, and a trade-off between them is analyzed. For the verification, the damped natural frequencies and mean square acceleration
Sharma, Rakesh Chandmal, Sharma, Sunil Kumar, Palli, Srihari, Rallabandi, Sivasankara Raju, Sharma, Neeraj
Journal Article
Development of Deep Reinforcement Learning Traction Controllers for Front and Rear Wheel Drive Electrified Vehicles2025-01-880304/01/2025
Traction control plays a key role in improving vehicle safety, especially for driving scenarios involving low levels of tire-road friction. Over the past 30 years, academic and industrial research in traction controllers has mainly favored deterministic approaches. This paper introduces a traction control strategy based on a deep reinforcement learning agent tailored for straight-line acceleration maneuvers from standstill in low-friction conditions. The proposed agent is trained on two different electric vehicles, a front-wheel drive city car (from EU vehicle segment A), and a rear-wheel drive sedan (from EU vehicle segment D). The paper presents a deep reinforcement learning agent formulation suitable for training on different vehicles, assesses the performance of the resulting controllers in comparison with a benchmarking integral sliding mode controller, and evaluates their response to changes in vehicle mass, powertrain parameters and tire-road friction conditions. The assessment
Caponio, Carmine, Mihalkov, Mario, Hankovszki, Zoltan, Fuse, Hiroyuki, Ivanov, Valentin, Sorniotti, Aldo, Gruber, Patrick, Montanaro, Umberto
Technical Paper
Concept of an Electromechanical Brake-By-Wire System for Battery-Electric Vehicles2025-01-880404/01/2025
Brake-by-wire systems have received more and more attention in the recent years, but a close look on the available systems shows, that they have not reached full by-wire level yet. Most systems are still using hydraulic connections between main cylinder and the brake calipers on at least one axle to ensure functional safety. Mostly, this is the front axle, since the front brakes have to convert more kinetic energy during braking manoeuvers. Electromechanical actuators are currently used for rear brakes in hybrid brake-by-wire applications solely, since a loss of the front brake calipers can lead to severe conditions and control loss of the vehicle during braking. Further, the higher mass of battery electric vehicles (BEVs) leads to much higher braking forces on both axles and to increased sizes of the electromechanical calipers. This article presents a concept for a brake-by-wire system for battery electric vehicles, which features electromechanical brake actuators on all corners and a
Heydrich, Marius, Lenz, Matthias, Ivanov, Valentin, Stoev, Julian, Lecoutere, Johan
Technical Paper
A Control and Fault-Tolerant Strategy Based on Electromechanical Brake System2025-01-826504/01/2025
With the development of automotive electrification and intelligent technology, vehicles have higher and higher requirements for braking systems. On the one hand, it requires it to have an active braking function, and at the same time facilitates the integration with other control systems of the chassis domain. The system should minimize oil pollution as much as possible, and under the premise of ensuring the pedal force, it can be used to recover the brake energy as much as possible to improve the range of electric vehicles as possible. The new brake system based on Electronic mechanical brake (EMB) as a line -controlled decoupling braking system can not only meet the needs of the brake pedal sensation, but also achieve continuous and accurate control of braking power. It can effectively Taking into account braking economy, braking safety, and braking comfort. In addition, the development of EMB technology is still immature and the failure rate is high, so research on EMB's fault
Li, Xuesong, Qin, Keyun, Zheng, Hongyu, Kaku, Chuyo
Technical Paper
Research on Energy Recovery Strategy in Braking of Electric Tractor-Semitrailer2025-01-829004/01/2025
Tractor-semitrailers play an important role in the transportation industry. However, global warming and the rapid advancement of energy technologies have driven the transformation of high-emission vehicles, such as tractor-semitrailers, to be powered by new energy sources in order to achieve goals related to energy conservation, emission reduction, and cost savings. By using the motor as the primary driving force, the energy recovered during braking or coasting can be converted into electricity and stored in the battery for later use. While much research has been conducted on braking control and energy recovery for passenger cars, there is limited research on tractor-semitrailers. Additionally, the jackknife is a critical factor to consider under high-speed conditions. To investigate the braking energy recovery of electric tractor-semitrailers, tire and motor models were developed based on the turning and braking conditions of such vehicles. Taking into account the load transfer effect
Chen, Runping, Duan, Yupeng
Technical Paper
An Integrated Data-Driven and Physics-Based Approach for Dynamic Operation Simulation of Electric Vehicles2025-01-860404/01/2025
To address the challenges of complex operational simulation for Electric Vehicles (EVs) caused by spatial-temporal variations and driver behavior heterogeneity, this study introduces a dynamic operation simulation model that integrates both data-driven and physics-based principles, referred to as the Electric Vehicle-Dynamic Operation Simulation (EV-DOS) model. The physics-based component encompasses critical aspects such as the powertrain energy transfer module, heat transfer module, charge/discharge module, and battery state estimation module. The data-driven component derives key features and labels from second-by-second real-world vehicle driving status data and incorporates a Long Short-Term Memory (LSTM) network to develop a State-of-Health (SOH) prediction model for the EV power pack. This model framework combines the interpretability of physical modeling with the rapid simulation capabilities of data-driven techniques under dynamic operating conditions. Finally, this study
Jing, Hao, HU, Jianyao, Ouyang, Jianheng, Ou, Shiqi(Shawn)
Technical Paper
Study on Emergency Obstacle Avoidance Lateral Stability Control of Tractor Semitrailer Vehicles2025-01-829604/01/2025
As a crucial component of highway freight systems, tractor semitrailer vehicles play a key role in the transportation industry. However, their complex vehicle structure can lead to significant lateral instability during emergency obstacle avoidance, posing challenges to the vehicle's dynamic stability and safety. To enhance the emergency obstacle avoidance lateral stability of tractor semitrailer vehicles, a direct yaw moment lateral stability control strategy based on differential driving/braking is proposed. First, a 3-degree-of-freedom ideal linear dynamic model of the tractor-semitrailer is established, and its accuracy is validated. Then, a lateral stability control strategy for emergency obstacle avoidance is proposed. The upper-layer controller employs an improved feedforward differential model-free adaptive control (IMFAC) method to track the target yaw rate and vehicle sideslip angle, while the lower-layer controller focuses on optimizing tire load rate. Additionally, a drive
Guo, Shaozhong, Dou, Jingyang
Technical Paper
High-Quality Clamping Force Control for Electro-Mechanical Brake Considering Nonlinear Disturbances2025-01-830404/01/2025
The Electro-Mechanical Brake (EMB) eliminates the traditional hydraulic pipeline arrangement through high-performance servo motor at the vehicles brake calipers. This provides a foundation for intelligent electric vehicles to achieve high-precision, fast response, and strong robustness in brake clamping force control. However, EMB faces some tricky nonlinear disturbances such as varying system stiffness disturbances, complex friction obstruction, etc., which leads to a decline in clamping force control performance. Therefore, this paper proposes a high-quality clamping force control for EMB considering nonlinear disturbances. First, we establish an EMB actuator model including the permanent magnet synchronous motor, mechanical transmission mechanism, and system stiffness characteristics. Next, the high-quality clamping force control strategy for EMB is designed. An outer-loop clamping force regulator is developed using Proportional-Integral-Derivative (PID) feedback control and
Zhao, HuiChao, Chen, Zhigang, Li, Lun, Wang, Zhongshuo, Wu, Jian, Chen, Zhicheng, Zhu, Bing
Technical Paper
Thermomechanical Fatigue Behavior of Gray Cast Iron in Brake Rotors2025-01-831904/01/2025
Gray cast iron is a cost-effective engineering material widely used for heavy duty engine blocks and brake rotor discs in vehicles. Thermomechanical fatigue (TMF) frequently occurs during vehicle operation due to temperature fluctuations in brake rotors. To speed up the design of the component, design structurally sounding brake rotors, and prevent premature thermally induced cracking, it is critical to investigate TMF behavior of the gray cast iron. This study presents a series of fatigue tests, including isothermal low cycle fatigue (LCF) tests at temperatures up to 700°C, as well as in-phase (IP) and out-of-phase (OP) TMF tests across various temperature ranges. Because of the asymmetric behavior in tension and compression, creep behaviors in both tension and compression and oxidation are also studied. These behaviors are the key to enable simulation of thermally induced cracks in rotors.
Liu, Yi, Lee, Heewook, Hess, Devin, Coryell, Jason
Technical Paper
Research on Pressure Control Methods for a Dual-Source Electro-Hydraulic Brake System with Redundant Braking Function2025-01-871604/01/2025
This paper presents a novel Dual-source Electro-Hydraulic Brake system (D-EHB) that incorporates a redundant braking module to enhance safety and reliability. The D-EHB is designed to address the critical issue of brake failure in vehicles, which can lead to severe accidents. The D-EHB system comprises two independent units: the Main Brake Unit (MBU) and the Redundant Brake Unit (RBU). Each unit has its own hydraulic power source. The MBU's hydraulic pressure is generated by a combination of a servo motor, ball screw, and servo piston, while the RBU has a simpler structure, with hydraulic pressure generated by a motor and plunger pump combination. Mathematical models for each component of the D-EHB have been developed and validated using AMESim. The mathematical models of each part were then combined to design a wheel cylinder hydraulic pressure estimation algorithm that can calculate the wheel cylinder pressure based on motor and valve output signals, making the system applicable to
Wang, Wenqiang, Zhao, Xuezhi, Shangguan, Wen-Bin, Ren, Bingyu
Technical Paper
Decelerations for Vehicles with Anti-Lock Brake Systems (ABS) during Wet-to-Dry Transitions on Asphalt and Concrete Road Surfaces2025-01-870304/01/2025
The braking performance of newer anti-lock braking system (ABS) equipped vehicles on roads with varying wetness levels is not well studied. Two late-model ABS-equipped vehicles were used to perform ABS-engaged braking tests on dry and wet asphalt and concrete surfaces from which vehicle speed and deceleration as a function of time were calculated. Tests were initially conducted on a dry surface before a water truck distributed water onto the road to create a wet road condition. A continuous series of tests were then performed until the road dried and the cycle was repeated multiple times. Across all tests of both vehicles on both road surfaces, deceleration levels generally decreased when the road was wet and returned to dry levels only when less than 25% of the road surface remained wet. Also, wet deceleration levels were high compared to the historical values used for wet roads. These findings provide a useful and readily identifiable boundary between what can be considered a dry and
Miller, Ian, King, David, Siegmund, Gunter
Technical Paper
Evaluation and Prevention of Brake Drum Freezing by Aerodynamic Measures2025-01-877504/01/2025
The use of drum brakes in Battery Electric Vehicles (BEVs) offers numerous benefits, including energy efficiency, reduced brake dust emissions, and reliable performance under challenging weather conditions. The capability of regenerative braking reduces the friction brake application frequency in BEVs and therefore the brakes can be prone to corrosion and performance degradation especially considering conventional disc brake systems. The closed design of a drum brake prevents corrosion of the friction-components by sealing out water, dirt or snow. A common sealing concept is performed with a labyrinth between the gap of the rotating drum and the axle mounted backplate. A hermetical isolation of water and snow ingress into the drum cannot be achieved with this concept, so additional aerodynamic measures are necessary to deflect the air/water path and protect the inner brake components. Additionally, interfaces like wheel cylinders, electric park brake parts, brake shoe pins, and axle
Hennicke, Tim, Kuthada, Timo, Bernhard, Adrian, Reichhart, Leander, Weber, Eugen, Moers, Michael, Rettig, Marc
Technical Paper
A Design of Electric Drive System for All-Wheel Drive Formula Student Racing Car to Improve Racing Performance2025-01-800504/01/2025
This paper introduces an innovative in-wheel electric drive system designed for all-wheel drive Formula Student Electric racing cars. The system utilized AMK's DD5-14-10-POW-18600-B5 model as the driving motor, with a gearbox transmission ratio of 13.2 determined through Optimum Lap simulation. A two-stage gear reducer was integrated into a unified hub-spoke assembly, which connected directly to the ten-inch carbon fiber rim. In this paper, three conventional FSEC planetary gear reducer shafting designs are introduced, and a new shafting structure is proposed. Then the four structures are compared in multiple dimensions. Subsequently, we designed the shafting of the gear group, determined the size parameters of the shafting structure and the bearing type, and completed the verification. The planetary carriers were integrated with the wheel-edge suspension columns. Meanwhile, a special floating brake disc mounting method was employed, which increased the brake disc's heat capacity by
Guo, Ruijie, Zeng, Junhao, Yang, Yuancai, Hou, Yijie, Zhu, Zhonghui, Xiong, Jiaming
Technical Paper
Advanced Driver Assistance Systems (ADAS): Assessing the Efficacy of Non-Impact Testing for Evaluating the Performance of Frontal Collision Mitigation Technology2025-01-805604/01/2025
As Automatic Emergency Braking (AEB) systems become standard equipment in more light duty vehicles, the ability to evaluate these systems efficiently is becoming critical to regulatory agencies and manufacturers. A key driver of the practicality of evaluating these systems’ performance is the potential collision between the subject vehicle and test target. AEB performance can depend on vehicle-to-vehicle closing speeds, crash scenarios, and nuanced differences between various situational and environmental factors. Consequently, high speed impacts that may occur while evaluating the performance of an AEB system, as a result of partial or incomplete mitigation by an AEB activation, can cause significant damage to both the test vehicle and equipment, which may be impractical. For tests in which impact with the test target is not acceptable, or as a means of increasing test count, an alternative test termination methodology may be used. One such method constitutes the application of a late
Kuykendal, Michelle, Easter, Casey, Koszegi, Giacomo, Alexander, Ross, Paradiso, Marc, Scally, Sean
Technical Paper
Fluid Topology Optimization for Heat Dissipation of Ventilated Brake Discs2025-01-818304/01/2025
Enhancing the heat dissipation performance of ventilated brake discs is a complex challenge involving fluid dynamics, solid mechanics, rotational motion, thermal transfer, and frictional interactions. To address this issue, this study developed a comprehensive simulation model for brake disc heat dissipation, informed by wind tunnel testing conducted on a multi-purpose vehicle (MPV) model. The research included a sensitivity analysis of design parameters related to the brake disc blades and employed a topology optimization approach to enhance the disc's heat dissipation capabilities. The study successfully demonstrated the applicability of topology optimization to the intricate thermal simulation of brake discs. As a result, a novel brake disc blade design with a unique geometry was developed, and the underlying principles contributing to its improved thermal performance were thoroughly analyzed. The optimized brake disc design, distinguished by a carefully contoured inlet curve and a
Zhao, Wentao, Jia, Qing, Qin, Lanwei, Xia, Chao, Chao, Han, Daxin, Jiang, Yang, Zhigang
Technical Paper
Material-Combined Vehicle Brake Disc Design for Enhanced Cooling Performance2025-01-818904/01/2025
The improvement of heat dissipation performance of ventilated brake discs is vital to braking safety. Usually, the technical approaches shall be material optimization or structural improvement. In this paper, a simulation model of the heat transfer of brake discs is established using STAR-CCM+ software. Cast iron, aluminum metal matrix composite (Al-MMC), and carbon-ceramic composite materials (C-SiC) are compared. The results show that: Al-MMC has better thermal conductivity so that a more uniform temperature gradient distribution shall be formed; C-SiC has poorer heat capacity yet, according to previous studies, it has better thermal stability, which is the ability to ensure its friction factor under high-temperature condition; cast iron performs better with convective heat transfer rate, which enhances the heat transfer between the surface and surrounding flow field. Based on the results, this paper proposes four types of material combined brake discs using different friction
Wang, Jiarui, Jia, Qing, Zhao, Wentao, Xia, Chao, Yang, Zhigang
Technical Paper
A Nonlinear Characteristics Identification and Compensation Control Method for Electromechanical Brake System2025-01-881004/01/2025
Clamping force control in Electromechanical Brake (EMB) systems must overcome various nonlinear characteristics, such as motor distorted voltage, Back Electromotive Force (EMF), and actuator friction disturbances. Therefore, modeling and parameter identification of these nonlinearities are necessary. This paper first proposes a motor parameter identification method based on the mathematical model of a Permanent Magnet Synchronous Motor (PMSM). A combination of the Least Square Method and Particle Swarm Optimization (PSO) is used to stepwise identify both the electrical and mechanical parameters of the motor. The accuracy of the identified parameters is validated by comparing simulation results with test bench responses. The identified parameters are applied to design the motor Back EMF compensation module, the distorted voltage compensation module, and to tune the current loop parameters. Next, a lumped parameter friction model suitable for closed-loop clamping force control in EMB
Qiao, Le, Xiong, Lu, Zhuo, Guirong, Shu, Qiang
Technical Paper
Bi-Level Control Co-Design for Parallel Electric-Hydraulic Hybrid Vehicles2025-01-858204/01/2025
This study presents a control co-design method that utilizes a bi-level optimization framework for parallel electric-hydraulic hybrid powertrains, specifically targeting heavy-duty vehicles like class 8 semi-trailer trucks. The primary objective is to minimize battery energy consumption, particularly under high torque demand at low speed, thereby extending both battery lifespan and vehicle driving range. The proposed method formulates a bi-level optimization problem to ensure global optimality in hydraulic energy storage sizing and the development of a high-level energy management strategy. Two nested loops are used: the outer loop applies a Genetic Algorithm (GA) to optimize key design parameters such as accumulator volume and pre-charged pressure, while the inner loop leverages Dynamic Programming (DP) to optimize the energy control strategy in an open-loop format without predefined structural constraints. Both loops use a single objective function, i.e. battery energy consumption
Taaghi, Amirhossein, Yoon, Yongsoon
Technical Paper
A Drive Anti-Slip and Lateral Stability Control Technique for Distributed Three-Axis Drive Vehicle2025-01-830304/01/2025
The research object of this project is the anti-slip and lateral stability control technique for a distributed three-axis drive vehicle. What differs from the traditional four-motor power system layout is that the third axle has two motors, while the second axle only has one motor. Compared with the traditional design, this layout can reduce dependence on battery performance and maintain motor operation in a high-efficiency range by switching between different operating modes. For example, when driving at high speeds, only the motor on the second axle works, which can improve motor efficiency. When accelerating or climbing, all motors work to provide a large power output. In the research, the vehicle model was first established in Simulink, and then co-simulated with TruckSim. The drive anti-slip control first identified the optimal slip rate for the road, and then used the sliding mode control to determine the driving torque for each wheel, achieving good control effects under various
Shen, Ruiteng, Zheng, Hongyu, Kaku, Chuyo, Zong, Changfu
Technical Paper
Dynamics Analysis and Stability Control of a Lunar Unicycle Self-Balancing Robot2025-01-830104/01/2025
The unicycle self-balancing mobility system offers superior maneuverability and flexibility due to its unique single-wheel grounding feature, which allows it to autonomously perform exploration and delivery tasks in narrow and rough terrains. In this paper, a unicycle self-balancing robot traveling on the lunar terrain is proposed for autonomous exploration on the lunar surface. First, a multi-body dynamics model of the robot is derived based on quasi-Hamilton equations. A three-dimensional terramechancis model is used to describe the interaction between the robot wheels and the lunar soil. To achieve stable control of the robot's attitude, series PID controllers are used for pitch and roll attitude self-balancing control as well as velocity control. The whole robot model and control strategy were built in MATLAB and the robot's traveling stability was analyzed on the lunar terrain.
Shi, Junwei, Zhang, Kaidi, Duan, Yupeng, Wu, Jinglai, Zhang, Yunqing
Technical Paper
Research on Anti-Slip Traction Control for Aircraft Engine-off Towing System2025-01-829204/01/2025
When the aircraft towbarless towing vehicle (TLTV) drives on road surfaces that are wet, icy, oily, or covered with debris, as well as under conditions such as overloaded towing, uneven distribution of aircraft weight, sudden acceleration and sharp turns, brake system failures, or severe tire wear, it may slip due to a mismatch between traction force and ground adhesion. As a key piece of ground support equipment at airports, the anti-slip performance of TLTV is crucial for ensuring safe and efficient ground movement of aircraft. With continuous advancements in control technology, extensive research has been conducted on anti-slip control strategies for TLTV. This paper reviews relevant literature in the field of anti-slip control for TLTV in recent years, focusing on the current status of anti-slip control technology development, control strategies, and the application of co-simulation technology in anti-slip control. Based on co-simulation using Matlab and Adams software, this paper
Yao, Yanan, Xu, Yitong, Zhu, Hengjia
Technical Paper
A Zero-Emissions Braking System: Experimental Setup, System Characterization and Model Validation2025-01-825004/01/2025
Following the current need of the automotive sector on reducing secondary emissions coming from non-exhaust sources, this paper presents an innovative zero-emissions magneto-rheological braking system, specifically designed to reach future brake emission targets while maintaining safety brake performance. In particular, the article focusses on the experimental setup design to evaluate a full-sized brake prototype under real load conditions and it presents the first experimental results. The zero-emission braking prototype has been developed for reaching performance compatible with the automotive application, specifically a segment-A vehicle, being able to generate enough braking torque as to perform an emergency brake maneuver without any other traditional braking system. A central aspect to confirm the system’s performance is the development of a test bench engineered for assessing the magneto-rheological braking technology. Detailed insights into the comprehensive strategy
Tempone, Giuseppe Pio, De Carlo, Matteo, Carello, Massimiliana, de Carvalho Pinheiro, Henrique, Imberti, Giovanni
Technical Paper
The Accuracy of Vehicle Speeds, Decelerations, and Brake Onset Times Calculated from Onboard Dash Cameras2025-01-869104/01/2025
Videos from cameras onboard a moving vehicle are increasingly available to collision reconstructionists. The goal of this study was to evaluate the accuracy of speeds, decelerations, and brake onset times calculated from onboard dash cameras (“dashcams”) using a match-moving technique. We equipped a single test vehicle with 5 commercially available dashcams, a 5th wheel, and a brake pedal switch to synchronize the cameras and 5th wheel. The 5th wheel data served as the reference for the vehicle kinematics. We conducted 9 tests involving a constant-speed approach (mean ± standard deviation = 57.6 ± 2.0 km/h) followed by hard braking (0.989 g ± 0.021 g). For each camera and brake test, we extracted the video and calculated the camera’s position in each frame using SynthEyes, a 3D motion tracking and video analysis program. Scale and location for the analyses were based on a 3D laser scan of the test site. From each camera’s position data, we calculated its speed before braking and its
Flynn, Thomas, Ahrens, Matthew, Young, Cole, Siegmund, Gunter P.
Technical Paper
Research on Torque Management Safety Monitoring Control for Hybrid Vehicles2025-01-857904/01/2025
Hybrid vehicles are driven by the vehicle controller, engine controller and motor controller through torque control, and there may be unexpected acceleration or deceleration of the vehicle beyond the driver's expectation due to systematic failure and random hardware failure. Based on the torque control strategy of hybrid vehicles, the safety monitoring model design of torque control is carried out according to the ISO 26262 safety analysis method. Through the establishment of safety goals and the analysis of safety concepts, this paper conducts designs including the driver allowable torque design for safety monitoring, the driver torque prediction design for safety monitoring, the rationality judgment design of driver torque for safety monitoring, the functional safety degradation design, and the engine start-stop status monitoring, enabling the system to transition to a safe state when errors occur. Firstly, the design of the driver's allowable torque includes the allowable requested
Jing, Junchao, Wang, Ruiguang, Liu, Yiqiang, Huang, Weishan, Dai, Zhengxing
Technical Paper
Research on Pedal Operation Characteristics for Detecting Pedal Misapplication2025-01-867504/01/2025
Drivers sometimes operate the accelerator pedal instead of the brake pedal due to driver error, which can potentially result in serious accidents. To address this, the Acceleration Control for Pedal Error (ACPE) system has been developed. This system detects such errors and controls vehicle acceleration to prevent these incidents. The United Nations is already considering regulations for this technology. This ACPE system is designed to operate at low speeds, from vehicle standstill to creep driving. However, if the system can detect errors based on the driver's operation of the accelerator pedal at various driving speeds, the system will be even more effective in terms of safety. The activation threshold of ACPE is designed to detect operational errors, and it is necessary to prevent the system from being activated during operational operations other than operational errors, i.e., false activation. This study focuses on the pedal operation characteristics of pedal stroke speed and
Natsume, Hayato, Shen, Shuncong, Hirose, Toshiya
Technical Paper
Research on Shuffle Reduction Control in Dual Motor Hybrid System Based on the Motor Torque Intervention2025-01-851704/01/2025
Due to the frequent and significant changes of the motor torque of hybrid vehicles during driving often occurring with the driving conditions, and the existence of the transmission tooth surface switching caused by the change in torque direction, as well as the underdamping characteristics caused by the relatively simple transmission system, the vehicle is prone to vehicle body shaking problems under conditions such as the transformation from acceleration conditions to energy recovery conditions, and exit from energy recovery. In order to ensure the ride smoothness of the hybrid vehicle while improving its power response performance, aiming at the underdamping characteristics of its transmission system, this paper develops a transmission PCM vibration suppression control strategy based on the vehicle control system to enhance the torque response and smoothness after Tip out or Tip in after braking. This strategy includes the identification of preconditions and the active intervention
Jing, Junchao, Zhang, Junzhi, Zuo, Botao, Liu, Yiqiang, Huang, Weishan, Xue, Tianjian
Technical Paper
Vehicle Motion Management - A Model Predictive Control Approach to Realize Holistic Redundancy to Enable Actuator Fail Operational Autonomous Driving2025-01-881204/01/2025
Since the introduction of ABS (1978), TCS (1986) and ESC (1995) in series production, the number of modern vehicle dynamics control functions and advanced driver assistance systems (ADAS) has been continuously increasing. Meanwhile, many functions are available that influence vehicle motion (vehicle dynamics). Since these are only partially and not hierarchically coordinated, the control of vehicle motion is still suboptimal. Current megatrends (automated driving, electromobility, software-defined vehicles) and new key technologies (steer-by-wire, brake-by-wire, domain-based E/E architectures) lead to an increasing number of electrified, motion-relevant components being introduced into series production. These components enable the development of an integrated chassis control (ICC) that controls all motion-relevant components, networks them with each other and coordinates them holistically to optimally control the vehicle motion regarding an adjustable desired driving behavior. Vehicle
Wielitzka, Mark, Ahrenhold, Tim, Vocht, Moritz, Rawitzer, Jonas, Schrader, Jonas
Technical Paper
Energy-Efficient Maneuvering of Connected and Automated Vehicles: NEXTCAR Phase II Results2025-01-838504/01/2025
Onboard sensing and Vehicle-to-Everything (V2X) connectivity enhance a vehicle's situational awareness beyond direct line-of-sight scenarios. A team led by Southwest Research Institute (SwRI) demonstrated 20% energy savings by leveraging these information streams on a 2017 Prius Prime as part of the first phase of the ARPA-E-funded NEXTCAR program. Combining this technology with automation can improve vehicle safety and enhance energy efficiency further. In the second phase, SwRI demonstrated 30% energy savings over the baseline. This paper summarizes the efforts to achieve 30% savings on a 2021 Honda Clarity PHEV. The vehicle was outfitted with the SwRI Ranger automated driving suite for perception and localization. Model-based control schemes with selective interrupt and control (SIC) were used to override stock vehicle controls and actuate the accelerator, brake, and electric power steering system, enabling drive-by-wire and steer-by-wire functionalities. Key algorithms contributing
Bhagdikar, Piyush, Gankov, Stanislav, Sarlashkar, Jayant, Hotz, Scott, Rajakumar Deshpande, Shreshta, Rengarajan, Sankar, Adsule, Kartik, Drallmeier, Joseph, D'Souza, Daniel, Alden, Joshua, Bhattacharjya, Shuvodeep
Technical Paper
Stability Control for Distributed Drive Electric Vehicles Using Particle Filter and Fuzzy Integral Sliding Mode Control2025-01-881104/01/2025
The Distributed Drive Electric Vehicles (DDEVs) offer advantages such as independently controllable driving and braking forces at each wheel, rapid response, and precise control. These features enable effective electronic stability control (ESC) by appropriately distributing torque across each wheel. However, traditional ESC systems typically employ single-wheel hydraulic differential braking, failing to fully utilize the independent torque control capabilities of DDEVs. This study proposes a hierarchical control strategy for distributed driving and braking ESC based on particle filter (PF) and fuzzy integral sliding mode control (FISMC). First, the vehicle state estimation layer uses a three-degree-of-freedom vehicle model and the PF to estimate sideslip angle and vehicle speed. Next, the target torque decision layer includes a target speed tracking controller and a yaw moment decision controller. The yaw moment decision controller uses the FISMC to determine additional yaw moment by
Li, Xiaolong, Zheng, Hongyu, Kaku, Chuyo
Technical Paper
Cost-Effective Sideslip Measurement: Beta for the People!2025-01-879604/01/2025
Vehicle sideslip is a valuable measurement for ground vehicles in both passenger vehicle and racing contexts. At relevant speeds, the total vehicle sideslip, beta, can help drivers and engineers know how close to the limits of yaw stability a vehicle is during the driving maneuver. For production vehicles or racing contexts, this measurement can trigger Electronic Stability Control (ESC). For racing contexts, the method can be used for driver training to compare driver techniques and vehicle cornering performance. In a fleet context with Connected and Autonomous Vehicles (CAVS) any vehicle telemetry reporting large vehicle sideslip can indicate an emergency scenario. Traditionally, sideslip estimation methods involve expensive and complex sensors, often including precise inertial measurement units (IMUs) and dead reckoning, plus complicated sensor fusion techniques. Standard GPS measurements can provide Course Over Ground (COG) with quite high accuracy and, surprisingly, the most
Hannah, Andrew, Compere, Marc
Technical Paper
Smart Boosting: A Control Strategy for Optimized Energy Management with Boost Converter in Hybrid Electric Vehicles2025-01-858004/01/2025
In hybrid electric vehicles (HEVs), optimizing energy management and reducing system losses are critical for enhancing overall efficiency and performance. This paper presents a novel control strategy for the boost converter in hybrid electric vehicles (HEVs), aimed at minimizing energy losses and optimizing performance by modulating to a higher boost converter voltage only when necessary. Traditional approaches to boost converter control often lead to unnecessary energy consumption by maintaining higher voltage levels even when not required. In contrast, the proposed strategy dynamically adjusts the converter's operation based on real-time vehicle demands, such as driver input, Engine Start-Stop (ESS) events, Active Electric Motor Damping (AEMD), entry and exit transitions for Engine Fuel Cut-Off (DFCO), Noise-Vibration-Harshness (NVH) events like lash-zone crossing and other specific operational conditions. The control strategy leverages predictive algorithms and real-time monitoring
Basutkar, Ameya, Huo, Shichao, Sullivan, Claire, Berger, Daniel, Tischendorf, Christoph
Technical Paper
Research on Composite Braking Strategy of Pure Electric Commercial Vehicle on Downhill Low-Adhesion Road Considering Rainfall Intensity2025-01-881304/01/2025
As a distributed wire control brake system, the electro-mechanical brake (EMB) may face challenges due to the need to integrate the actuator in the limited space beside the wheel. During extended downhill braking, especially on wet roads with reduced adhesion, the EMB must operate at high intensity. The significant heat generated by friction can lead to thermal deformation of components, such as the lead screw, compromising braking stability. This paper focuses on pure electric light trucks and proposes a tandem composite braking method. This approach uses an eddy current retarder (ECR) or motor to provide basic braking torque, while the EMB supplies the dynamic portion of the braking torque, thereby alleviating the braking pressure on the EMB. First, a driver model, tire model, motor model, and braking models are developed based on the vehicle's longitudinal dynamics. In addition, the impact of various factors, such as rainfall intensity, road slope, ramp length and vehicle speed, on
Liu, Wang, Zhang, Yu, Xiao, Hongbiao, Shen, Leiming
Technical Paper
Research on Automatic Emergency Braking Pedestrian System Considering Road Adhesion Coefficient10-09-03-002203/08/2025
To further optimize the automatic emergency braking for pedestrian (AEB-P) control algorithm, this study proposes an AEB-P hierarchical control strategy considering road adhesion coefficient. First, the extended Kalman filter is used to estimate the road adhesion coefficient, and the recursive least square method is used to predict the pedestrian trajectory. Then, a safety distance model considering the influence factor of road adhesion coefficient is proposed to adapt to different road conditions. Finally, the desired deceleration is converted into the desired pressure and desired current to the requirements of the electric power-assisted braking system. The strategy is verified through the hardware-in-the-loop (HIL) platform; the simulation results show that the control algorithm proposed in this article can effectively avoid collision in typical scenarios, the safe distance of parking is between 0.61 m and 2.34 m, and the stop speed is in the range of 1.85 km/h–27.64 km/h.
Wang, Zijun, Wang, Liang, Ma, Liang, Sun, Yong, Li, Chenghao, Yang, Xinglong
Journal Article
Anti-Noise Brake Pads Shims: T-Pull Test and Bond CoverageJ2694_202503 (Current)03/05/2025
This recommended practice covers the attachment of bonded anti-noise brake pad shims only. Mechanically attached shims (those without bonding) are not covered by this procedure.
Brake Linings Standards Committee
Recommended Practice
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